γ-Glutamylcysteine synthetase (γ-GCS) as a target for overcoming chemo- and radio-resistance of human hepatocellular carcinoma cells.

Aims: This study uncovered that the genetically endowed intracellular glutathione contents (iGSH) regulated by the catalytic subunit of γ‑glutamylcysteine synthetase heavy chain (γ‑GCSh) as a prime target for overcoming both the inherited and stimuli-activated chemo- and radio-resistance of hepatocellular carcinoma (HCC) cells.

Main Methods: Reactive oxygen species (ROS) production and mitochondrial membrane potential (Δψm) were determined by the probe-based flow cytometry. The TUNEL assay was used as an index of radio-sensitivity and the MTT assay was used as an index of chemo-sensitivity against various anti-cancer agents.

Cisplatin-induced regulation of signal transduction pathways and transcription factors in p53-mutated subclone variants of hepatoma cells: Potential application for therapeutic targeting.

Cisplatin is commonly recognized as a DNA-damaging drug; however, its versatile antitumor effects have been demonstrated to extend beyond this narrow functional attribute. The present study determined how cisplatin regulates alternative pathways and transcription factors to exert its additional antitumor actions. Cisplatin was observed to be able to trigger an endoplasmic reticulum stress response through aggravated nitrosative stress coupled to perturbed mitochondrial calcium (Ca) homeostasis, which substantially downregulated glucose-regulated protein (GRP) 78 expression by suppressing the cleavage of activating transcription factor (ATF) 6α (90 kDa) to its active 50 kDa subunit.

Folate deficient tumor microenvironment promotes epithelial-to-mesenchymal transition and cancer stem-like phenotypes.

Clinically, serum level of folate has been negatively correlated to the stage and progression of liver cancer. Nevertheless, the functional consequence of folate deficiency (FD) in malignancy has not been fully investigated. Human hepatocellular carcinoma (HCC) cells (as study model) and other cancer types such as lung and glioma were cultured under folate deficient (FD) and folate complete (FD) conditions.

Folate Deficiency Triggered Apoptosis of Synoviocytes: Role of Overproduction of Reactive Oxygen Species Generated via NADPH Oxidase/Mitochondrial Complex II and Calcium Perturbation.

Despite a plethora of literature has documented that osteoarthritis (OA) is veritably associated with oxidative stress-mediated chondrocyte death and matrix degradation, yet the possible involvement of synoviocyte abnormality as causative factor of OA has not been thoroughly investigated. For this reason, we conduct the current studies to insight into how synoviocytes could respond to an episode of folate-deprived (FD) condition. First, when HIG-82 synoviocytes were cultivated under FD condition, a time-dependent growth impediment was observed and the demise of these cells was demonstrated to be apoptotic in nature mediated through FD-evoked overproduction of reactive oxygen species (ROS) and drastically released of cytosolic calcium (Ca2+) concentrations.

Proteomic Characterization of Annexin l (ANX1) and Heat Shock Protein 27 (HSP27) as Biomarkers for Invasive Hepatocellular Carcinoma Cells.

To search for reliable biomarkers and drug targets for management of hepatocellular carcinoma (HCC), we performed a global proteomic analysis of a pair of HCC cell lines with distinct differentiation statuses using 2-DE coupled with MALDI-TOF MS. In total, 106 and 55 proteins were successfully identified from the total cell lysate and the cytosolic, nuclear and membrane fractions in well-differentiated (HepG2) and poorly differentiated (SK-Hep-1) HCC clonal variants, respectively. Among these proteins, nine spots corresponding to proteins differentially expressed between HCC cell types were selected and confirmed by immunofluorescence staining and western blotting.

A Novel Microtubule-Disrupting Agent Induces Endoplasmic Reticular Stress-Mediated Cell Death in Human Hepatocellular Carcinoma Cells.

Here, we present evidence of a novel microtubule-disrupting agent, N-deacetyl-N-(chromone-2-carbonyl)-thiocolchicine (TCD), exhibiting potent antitumor activity (with IC50 values in the nanomolar range) against hepatocellular carcinoma cell lines. Cell cycle analysis revealed that TCD induced G2/M cell-cycle arrest in a dose- and time-dependent manner in both Hep-J5 and Mahlavu HCC cell lines. TCD also induced a decrease in mitochondrial membrane potential (ΔΨm) and caused DNA damage.

Folate deficiency-triggered redox pathways confer drug resistance in hepatocellular carcinoma.

Patients with hepatocellular carcinoma (HCC) are prone to folate deficiency (FD). Here we showed that, in cell line-specific manner, FD caused resistance to FD-induced oxidative stress and multi-drug resistance (MDR). This resistance was due to upregulation of glucose-regulated protein 78 (GRP78) and Survivin.

Paclitaxel pretreatment overcomes hypoxia inducible factor-1α-induced radioresistance acquisition of human hepatoma and lung adenocarcinoma cells.

Aims: This study delineated the mechanisms of paclitaxel (PTX) assistance in overcoming radioresistance in hepatoma and human lung adenocarcinoma (HLAC) cells.

Main Methods: The TUNEL assay was used as an index of radiosensitivity, and the MTT assay assessed the efficacy of various combined PTX/RT treatments. The efficacy of PTX disruptions of hypoxia-inducible factor-1 alpha (HIF-1α) was assessed using Western blotting.

Folate deficiency triggers an oxidative-nitrosative stress-mediated apoptotic cell death and impedes insulin biosynthesis in RINm5F pancreatic islet β-cells: relevant to the pathogenesis of diabetes.

It has been postulated that folic acid (folate) deficiency (FD) may be a risk factor for the pathogenesis of a variety of oxidative stress-triggered chronic degenerative diseases including diabetes, however, the direct evidence to lend support to this hypothesis is scanty. For this reason, we set out to study if FD can trigger the apoptotic events in an insulin-producing pancreatic RINm5F islet β cells. When these cells were cultivated under FD condition, a time-dependent growth impediment was observed and the demise of these cells was demonstrated to be apoptotic in nature proceeding through a mitochondria-dependent pathway.

Novel spectrophotometric method for the quantitation of urinary xanthurenic acid and its application in identifying individuals with hyperhomocysteinemia associated with Vitamin B₆ deficiency.

A novel spectrophotometric method for the quantification of urinary xanthurenic acid (XA) is described. The direct acid ferric reduction (DAFR) procedure was used to quantify XA after it was purified by a solid-phase extraction column. The linearity of proposed method extends from 2.

Overexpression of GRP78 is associated with malignant transformation in epithelial ovarian tumors.

Aim: Glucose-regulated protein 78 (GRP78) is one of the best-characterized endoplasmic reticulum chaperone proteins. The aim of this study was to explore the potential implications of GRP78 in the development of epithelial ovarian carcinomas (EOCs) and the possible clinical usefulness of GRP78 expression as a prognostic biomarker for EOCs.

Materials And Methods: A total of 133 women were enrolled.

Survivin-mediated cancer cell migration through GRP78 and epithelial-mesenchymal transition (EMT) marker expression in Mahlavu cells.

Background: Survivin has multiple functions during the progression of cancer. However, the role of survivin in the progression and metastasis of hepatocellular carcinoma (HCC) remains unknown.

Materials And Methods: Survivin expression in HCC cells (Mahlavu and Hep3B) was assessed using reverse transcription real-time PCR and Western blot analyses.

Glucose-regulated protein 78 (GRP78) mediated the efficacy to curcumin treatment on hepatocellular carcinoma.

Background: Glucose-regulated protein 78 (GRP78) plays an important role in the therapeutic treatment and progression of cancer. However, little is known about the effect of GRP78 expression to curcumin in hepatocellular carcinoma (HCC).

Materials And Methods: In this study, we generated GRP78 knockdown cells (GRP78KD) by a short interfering RNA (siRNA) technique.

Normoxically overexpressed hypoxia inducible factor 1-alpha is involved in arsenic trioxide resistance acquisition in hepatocellular carcinoma.

Background: The aim of this study was to examine the underlying signaling mechanisms of arsenic trioxide (ATO)-mediated anticancer effects and the responsible biomarker(s) for the acquired resistance in human heptatocellular carcinoma (HCC).

Materials And Methods: The therapeutic effects of ATO were examined using 2 characteristically distinct HCC cell lines, Hep-J5 (overexpressing HIF-1α/GRP78) and SK-Hep-1 (the matched control). ATO-mediated proliferation inhibition, oxidative stress, and apoptosis were analyzed using flowcytometric analysis and western blotting.

6-dehydrogingerdione sensitizes human hepatoblastoma Hep G2 cells to TRAIL-induced apoptosis via reactive oxygen species-mediated increase of DR5.

The anticancer effects of 6-dehydrogingerdione (6-DG), a compound isolated from the rhizomes of Zingiber officinale , and its mechanisms of sensitization to TRAIL-induced apoptosis were studied using human hepatoblastoma Hep G2 cells. This study demonstrates for the first time that 6-DG-induced apoptosis might be executed via mitochondrial- and Fas receptor-mediated pathways. Further studies also demonstrated that 6-DG could sensitize Hep G2 cells to TRAIL-induced apoptosis.

Is the blood donated by habitual nut quid chewers suitable for use in transfusion?

Background/purpose: Betel quid (BQ) chewing is a popular oral masticatory activity, and there are approximately 600 million BQ chewers worldwide. Although chewing BQ has been linked to the patho-genesis of oral cancer, leukoplakia, and oral submucous fibrosis. The question whether the mixed constituents present in areca nut, which may exert cytotoxic effects on red blood cells (RBCs), has never been addressed.

Glucose-regulated protein 78 (GRP78) silencing enhances cell migration but does not influence cell proliferation in hepatocellular carcinoma.

Background: GRP78 plays an essential role in embryonic development and in the therapeutic treatment and progression of cancer. However, little is known about the role of GRP78 in hepatocellular carcinoma (HCC).

Methods: In this study, we characterized five different HCC cell lines to examine GRP78 expression patterns and found that only HepJ5 cells ectopically overexpress GRP78.

Verteporfin-photoinduced apoptosis in HepG2 cells mediated by reactive oxygen and nitrogen species intermediates.

Photodynamic therapy (PDT) is a rapidly evolving treatment modality with diverse usages in the field of cancer therapy. Most of PDT is based on free radical-mediated photo-killing of cancer cells. This study aimed to elucidate the detailed cascade of events that lead to apoptotic cell death of HepG2 cells resulting from the photodynamic effect (PDE) of verteporfin.

Glucose-regulated protein 78 is a novel contributor to acquisition of resistance to sorafenib in hepatocellular carcinoma.

Background: Sorafenib is a newly established cancer drug found to be an effective systemic treatment for advanced hepatocellular carcinoma (HCC). However, little is known about any potential effectors that modify tumor cell sensitivity towards sorafenib. Here, we present the first evidence that glucose-regulated protein 78 (GRP78) is intimately associated with acquisition of resistance towards sorafenib.

Sorafenib induces preferential apoptotic killing of a drug- and radio-resistant Hep G2 cells through a mitochondria-dependent oxidative stress mechanism.

Sorafenib (Nexavar, BAY43-9006), a bi-arylurea, is a newly established anti-cancer drug and its functional attribute of cytotoxicity is based on the multi-kinase inhibitory action. Here, we report yet another novel pathway in which sorafenib can induce apoptotic cell death preferentially and efficaciously on an experimentally proven drug- and radio-resistant human Hep G2 cells via a mitochondria-dependent oxidative stress mechanism. A real time confocal imaging assay revealed that sorafenib could rapidly provoke the production of ROS plethorically, mainly concentrating in the mitochondria, albeit substantial amounts of ROS could also be detected in cytosol and nucleus.

Distinct differences in the induction of stimulus-mediated superoxide generation by polymorphonuclear neutrophils isolated from patients with different types of leukemia.

Background/purpose: Accumulating literature has documented that there exists a distinct difference in nitro blue tetrazolium reduction capacity by the polymorphonuclear neutrophils (PMNs) from patients with different types of leukemia. The underlying mechanism associated with this observed phenomenon remains to be clarified.

Methods: The production of O2-, monitored by a validated probe (lucigenin)-based ultraweak chemiluminescence, in resting and/or phorbol-1,2-myristate-1,3-acetate (PMA)- and zymosan-stimulated systems of various leukemic PMNs was measured.

(-)-Anonaine induces apoptosis through Bax- and caspase-dependent pathways in human cervical cancer (HeLa) cells.

(-)-Anonaine has been shown to have some anticancer activities, but the mechanisms of (-)-anonaine inducing cell death of human cancer cells is not fully understood. We investigated the mechanisms of apoptosis induced by (-)-anonaine in human HeLa cancer cells. Treatment with (-)-anonaine induces dose-dependent DNA damage that is correlated with increased intracellular nitric oxide, reactive oxygen species, glutathione depletion, disruptive mitochondrial transmembrane potential, activation of caspase 3, 7, 8, and 9, and poly ADP ribose polymerase cleavage.

Protective effects of a freeze-dried extract of vegetables and fruits on the hydroxyl radical-mediated oxidative damage of DNA and decrease of erythrocytes deformability.

The protective effects of a freeze-dried extracts of vegetables and fruits (BauYuan; BY) on the hydroxyl radical-mediated DNA strand breakages and the structural integrity of human red blood cells (RBCs) were investigated. First, the supercoiled plasmid (pEGFP-C1) DNA was subjected to oxidation damage by an ascorbate-fortified Fenton reaction and the protective effects were analyzed by agarose gel electrophoresis. In the absence of BY extracts, exposure of the high-throughput .

Cholestin (Monascus purpureus rice) inhibits homocysteine-induced reactive oxygen species generation, nuclear factor-kappaB activation, and vascular cell adhesion molecule-1 expression in human aortic endothelial cells.

Hyperhomocysteinemia is associated with dysfunction and an independent risk factor of cardiovascular diseases. Cholestin (Monascus purpureus-fermented rice), contains a naturally-occurring statin, which has lipid-modulating and anti-inflammatory effects. We investigated the effects of Cholestin extract on the expression of vascular cell adhesion molecule-1 (VCAM-1) by homocysteine (HCY)-treated human aortic endothelial cells (HAECs).